Misleading error message if sqlite3 is not installed as exception is swallowed

[jjackson]

This is similar to #1673, which has been fixed. But there is still a case when this can happen:

from root/django/trunk/django/db/backends/sqlite3/base.py

14 	try:
15 	    try:
16 	        from sqlite3 import dbapi2 as Database
17 	    except ImportError:
18 	        from pysqlite2 import dbapi2 as Database
19 	except ImportError, e:
20 	    import sys
21 	    from django.core.exceptions import ImproperlyConfigured
22 	    if sys.version_info < (2, 5, 0):
23 	        module = 'pysqlite2'
24 	    else:
25 	        module = 'sqlite3'
26 	    raise ImproperlyConfigured, "Error loading %s module: %s" % (module, e)

If the first import fails, and then the second import fails, you'll get this error message: "ImproperlyConfigured: Error loading sqlite3 module: No module named pysqlite2" when the error may really be that there was no module named sqlite3 available. (That was my particular problem.) The 'module' variable gets set based on the sys.version, but the exception is based on whichever one last failed. There's no pysqlite2 in Python 2.5, so if the first import fails under 2.5, you're going to get the misleading error message.

[Malcolm Tredinnick]

(In [9060]) Fixed #9113 -- Improved exception message reporting when importing sqlite3 fails.